Depending on if you’ve set up bbPress so that it’s not only integrated but also uses WordPress’s functions when available, I think you can just call the WP function. If it doesn’t work, you need to make a database query along the lines of:
global $bbdb;
$profiledata = $bbdb->get_row( "SELECT meta_value FROM $bbdb->usermeta WHERE meta_key = $theprofiledetail AND user_id = $theuserid");
Where $theuserid and $theprofiledetail are set to whatever you want. Note that $profiledata is worth examining by using print_r($profiledata);
or the like, because its format can be confusing. The code might not work, but it’s an idea.